Sanding machine



May 30, 1933. P. A. soLEM SANDING MACHINE Filed Oct. 16. 1925 2Sheets-Sheet 1 May 30, 1933. P. A. SOLEM SANDING MACHINE Filed Oct. 16.1925 2 Sheets-Sheet 2 IIIIIIIIIIII Patented May 30, 1933 EiC E PETER A.SOLEM; OF ROCKFORD, ILLINOIS V SANDING MACHINE Application filed.October 16, 1925. Serial No. 62,694.

This invention relates in general to abrading machinery and isparticularlyconcerned with sanding machines of the endless bed typewhich employ rotating sandlng or abrading drums or cylinders.

In machines of the kind mentioned, the drums are usually given apositive, oscillating, endwise movement to secure a smooth finish on thestock operated upon. One of the principal objects of the presentinvention is to provide an improved means for accomplishing theoscillating movement which 1mposes no weight on the drum shafts, such asordinarily caused uneven contact of the drums with the stock because ofa whipping v action produced at the free end of the drum shafts,and wasfurthermore a cause of quick wearing of the bearings of the drum shafts.lt has also been the custom to provide separate motors for the separatedrum shafts, usuallv coupled to the shafts in such a way as'to permitadjustment of the elevation of the abrading drums relative to the work.M This usually resulted in the motor armature shaft being considerablyout of llne wi ththe drum shaft, giving poor power transmissmn, imposingheavy loads on the shaft bearings, and resulting in noisy operation,while at the same time necessitating separate supporting brackets forthe motors and greater over-all dimensions of the machine as a result ofthe intermediate drive couplings. A further object of this invention isto eliminate these objectionable features of previous machines by theprovision of built-in motors giving direct drive for the drum shafts. Asa. re? sult of the rotors being part of the drum shafts, the motorremains in line with the drums whether the heaviest or lightest cuts aremade. Greater compactness and aconsiderable reduction in the over-alldimensions are secured and a saving in floor space is effected. 7

Still other objects and advantages of. the present invention will be"discussed more fully in the following detailed description in whichreference is made to the accompanying drawings, wherein Fig.1 is a sideelevation of a sander of the endless bed type incorporating theimprovements of my invention;

Fig. 2. is a transverse section through the machine and is taken on theline 2--2 of Fig. 1 looking in the direction of the arrows, portions ofthe drum and frame being broken away to conserve space in the'drawings;

Fig. 3 is an enlarged fragmentary sectional detail of the motor housingandits mounting, an intermediate portionof the shaft for the drum andarmature being broken away at the armature;

Fig. 4 is a similar enlarged sectional detail taken at the opposite endof the shaft for the drum and armature and showing the'connection withthe rock-er arm; and i Fig. 5 is an enlarged sectional detail of one ofthe eccentrics for actuating the rocker arms and is taken on the line5-5 of Fig. 2 looking in the direction of the arrows.

Throughout the views the same reference numerals are applied tocorresponding parts.

The sanding machines of the type to which the present improvements areintended to be applied usually comprise a base 6 having heavy uprightside frame pieces? and 8 extending therefrom and suitably fixed togetherin spaced relation. The frame'provides supports for ways over which anendless bed 9 is arranged to move. The bed 9 consists of steel slatswith rubber pads secured thereon, the slats being in turn secured onroller chains operatingon sprockets having bearings at 10 and 11 atopposite ends of the machine. The driving of the bed is through theintermediary of suitable transmission from a shaft 12 bearing in'theframe of the machine and suitably driven by a motor supported on abracket at the side of the machine. The shaft 12 is shown in section andthe motor referredto is not shown. 7 'Apulley 13 suitably mounted on theshaft 12 is provided for driving pulleys'14 and 15'. The

- pulley 14; by virtue'of its position above the bed 9 is arranged todrive a brush for clean ing the stock passing out of the machine and thepulley 15 by virtue of its position below the bed is arranged to drive abrush for cleaning the under side of the bed 9. The belt 16, passingabout the pulleys referred plurality of pressure bars 22 are providedbetween the abrading drums which have polished under faces for thepassage therebeneath of the stock operated upon. The abrading drums arecapable of adjustment as to elevation for lightor heavy cuts, usually bythe simultaneous adjustment of the elevation of the drum shaft bearings,by the operation of worms 23 on the ends of shafts 24. The latter arefitted with hand Wheels 25 for convenient manual operation from the sideof the machine. The worms .23 mesh with worm wheels 26 to operate jackscrews 27 to raise and lower the shaft bearings rela tive to bosses 28provided on the frame of the machine. is given simple rotation for theinitial rough finishing out. In this case, the drum 18 is arranged forsimple rotation at the intake end of the machine. -The other drums 19and20 are arranged to have endwise oscillation or reciprocation duringrotation. By this compound movement it has been found that the grade offinish on the stock is highly improved as the fibers of the wood are notdrawn or strung out and left in loose fuzz or fur on the surface of thestock. The drums are usually oscillated by rocker arms orrbeams 29 whichhave a suitable thrust bearing connection with the drum shafts.

' 3 The rocker arms-are suitably driven by a direct gearing connectionwith the shaft 12, consisting of bevel gears 30and 31. The gear 31 isfixed on the shaft 32, which operates eccentrics, as will presentlyappear, to

' I communicate a rocking motion to the arms 29. In this way theoscillating motion of the drums with the drum shafts occurs only duringthe feeding movement of theendless bed 9, that is, during the normaloperation of the machine. For the mostpart, the foregoing arrangement iscommonly employed in sanding machines of this type and no invention isclaimed: therein except injso far as the improvements hereinafterreferred to are tied 7 up with this arrangement.-

Referring now more particularly to Fig. 2, the drum 19, or for thatmatter the drum 20, is mounted on a shaft 33 supported in bearings at 34and '35 on the frame pieces 7 and 8 at opposite ends of the drum. Ac-

cordingto the present invention, the housing 36 of the motor 21 issupported in the bearing 35 in a'manner more particularly describedhereinafter for adjustment as to elevation simultaneously withthebearings 34 and 35. The shaft 33is in a single con- Usually the firstdrum of the set tinuous piece without the interposition of a coupling orany intermediate transmission for the driving of the drum shaft from thearmature shaft, since the rotor or armature shaft is integral with thedrum shaft. This improvement thus broadly defined, it will beappreciated, accomplishes several highly desirable advantages. First ofall, it is definitely insured that the armature and the drumwill remainin line at all times regardless of whether a heavy or light cut is beingmade, the two being kept in the same rela tion to one another in anystate of adjustment. Furthermora the mounting of the motor housing onthe same vertically adjustable support with the shaft bearing insureskeeping the same relation between the armature and its field coils inthe housing, regardless of the amount of adjustment. The directness ofthe driving connection resulting from the shaft for the armature anddrum being in one piece gives smooth and noiseless operation. There isavoided the pounding and vibration at the coupling which, besides beingnoisy, was a contributing factor in the wearing out of the drum shaftbearings. Thearrangement conduces toward the best obtainable compactnessand the over-all dimensions are very much reduced so that in trunnionsprovided on the forked end 40 r of therocker arm. The rocker arm 29 ispivoted at 41 to a link 42, which in turn is pivoted at .43'on a bracket44 bolted 'tothe side of the adjacent frame piece 7. The bracket 44provides a ledge at 45 on which one end of a coiled compression'spring46 rests, while its other end is in contact with the under side of thelink 42. The lower end of the arm 29 is pivoted at 47 to a link 48having a split strap end 49 enclosing an eccentric 50 secured on theshaft 32, as by means of a tapered pin 51 (see Fig. 5). The shaft 32 issupported in bearings provided in brackets 52 on the side of the framepiece 7. The eccentric- 50 and the end 49 of the link 48 are maintainedin proper relation by a collar 53 secured on .theend, of the shaft 32 bya tapered pin '54. It will appear that the weight of the rocker arm 29is substantially counterbalanced by the compression of the spring 46 andnone of the weight of the arm is imposed on the shaft 33. The arm is infloating relation to the collar 38 and the shaft 33. This avoids thedeflecti on of the projecting end of the shaft and elimihates thewhipping action and consequent vibration, which in previousmachinesresultedalso is the provision of a vibrationless and smoothly operatedoscillating drive. Both improvements contribute toward considerableimprovement in the grade of the work produced by the machine. They alsoare factors in prolonging the life of the bearings'for the drum shaftsand in this way reduce operating costs and give generally betterefiiciency. The provision of eccentrics as separate pieces assembled onthe shaft 32 enable cheap and easier replacements. he takeup bolts onthe split strap ends of the links 48 permit compensating for. wear sothat a close'working fit for the links on the eccentrics 50 can bemaintained at all times.

Referring for the present more particularly to Fig. 3, it will be notedthat the housing 36 of the motor 21 has the bell ends and 56 providingspaced armature shaft bearings. The bell end 55 is bolted to thebearing35 as indicated at 57. A cap 58 bolted on the bearing 35 positions anouter ball race member 59 between the hollow neck 60 thereof, and asimilar hollow neck 61-on the bell end 55 of. the motor housing. Therace member 59 and the. necks 60 and .61 are all received snugly withinthe bore 62 of the bearing 35, and the race member 59 is held stationarybetween the necks 60 and 61 in an obvious manner. Anti-friction balls 63operate between the outer race 59 and an inner race 64. The race 64: isof elongated collar form and has a sleeve 65 slidable therein. Thesleeve65 is fixed, as by means of a pin 66. against rotation relative to theshaft 33, the pin 66 being received in a notch 67 provided at the end ofthe'sleeve 65 where the sleeve comes in contact with a shoulder68,.pr0vided by an enlargement in the diameter of the shaft 33. It willappear that the rotation of the sha t 33 with the sleeve 65 and theinner race. member 64: is permitted and is rendered almost frictionlessby the provision of the balls 63. At the same time, the telescopingrelation of the sleeve 65 in the inner race 64 permits the oscillationof the shaft 33 with the abrading drum as previously described. Thisfeature is covered in my copending application Serial No. 416,523 filedDecember 26. 1929. The lubrication of the sliding jointbetween thesleeve and the race is induced by rings 69 dipping in the oil in thebottom of the chamber provided about the shaft within the hollow necks60 and 61.

The lubricant is retained in the chamber referred to by packing providedat 7 O in the cap 58 and bell piece 55.

The armature core, the end of which appears at 71, is suitably splinedon the shaft- 33 and rests in engagement with a shoulder afforded by anenlargement of the diameter;

of the shaft 33. A spacing sleeve 7 3 abuts against the end of thearmaturecore 71 at one end and at its other end abuts against theadjacent end of the bearing sleeve 65, thereby keeping the sleeve 65 inproper re lation to its ball bearing in an obvionsman The sleeve 7 3 ispreferably of the samediameter and of the same length as the sleeve ROI.

65 to be interchangeable therewith. For this reason, it is also providedwith a notch 67 in one end thereof to receive the pin 66 when the sleeve7 3 is substituted for the sleeve 65. The purpose in this provision isto obviate having to shut the machine down for an extended period in theevent the sleeve 65 be-' comes worn to any appreciable degree. With thespacing, sleeve substituted for the bearing sleeve and the bearingsleeve 'in turn performingthe function of the spacingsleeve, the machinemay be keptnn serv ce and necessary replacement sleeves ordered from themanufacturer of he machine or otherwisemade to have in readiness whenanother replacement is necessary.- This feaf ture'is also covered' 1nthe copending appl1-' cation mentioned above. The stepping n thediameter of the shaft toward the outer end affording the shoulders at 68and'4'2, etc. enables the removal of the parts and ea-sy 'replacementthereof. i i l t The outer end f the shaft 33 is received in a bearingheld in thebellend 56 of the motor housing 36. A. capZ l is bolted tothe ,bell' end 56, as shown, clamps an outer race 75 in placeQ Theanti-friction bearing balls 76 operate between vthe outer race 7 5 and.an inner race 77. The latter similarly to the race 6a is extended in theform of. a collar and arranged to slide freely on a bearing sleeve 7 8which, like the sleeves 65 and 73, is renewable. The sleeve 7 8 is heldin engagement at one end with a shoulder 79, providod by anenlargementin the diameter of the shaft 33, by means of a disc at itsother end bolted, as at 81, to the free end of the shaft 33. This alsoforms part of the subject matter of the copending application abovementioned. he loose'rings'82 serve.'in'thisinstance the same function asthe rings 69; to feed lubricating oil onto the sliding joint between thesleeve 78 and the race 77. It is apparent that the arrangement providesfor the compound movement of the shaft 33 by the sliding of the sleeve78 in the race 7'? and the rotation of the innerrace' relative to theouter race.

Referring now to l, it will be seen that the oppositeend of the shaft 33from the end previously under consideration has similar provisions inthe bearing 34 for permitting simultaneous rotation and reciprocation ofthe shaft in anti-friction bearings. A pair of caps 83 are bolted to theopposite sides of the'bearing 34 and clamp the outer race 8; betweenthem inan obvious manner. The bearing balls 85 are held between theouter race -84 and an inner race 86 sliding on the bearing sleeve 87.This sleeve is held in engagement with the shoulder 88 by aspacingslteve 89. The latter is in turn held in place by the inner race 90 ofan anti-friction bearing within the thrust collar 38'. The sleeves 89and 87 are interchangeable in like manner to the sleeves and 73, ascovered in the copending application. The inner race 90 is held in placeby a collar 91, secured as by means of a tapered pin 92 to the free endof the shaft 33. The outer race 93 for the balls 94 is held within thethrust collar 38 behind a cap 95 which bolts on the end of the collar38. It will thus be seen that the provision of anti-friction bearings isextended throughout the machine so far as practicable with a saving inoperating costs and an increase in general efiiciency.

I claim:

1. A machine as set forth in claim 5 wherein the shaft bearing supportson the machine frame members are vertically adjustable whereby to adjustthe drum with its shaft according to the work to be handled, saidcounterbalancing means for said rocker arm being practically unaffectedby such vertical adj stment of said shaft with its bearings by reason ofthe fact that the adjustment is slight.

2. A machine as set forth in claim 6 wherein the shaft bearing supportson the machine frame members are vertically adj ustable whereby toadjust the drum with its shaft according to the work to be handled, saidpivotal mounting for the rocker arm with the yielding counterbalancingmeans therefor being arranged to be practically unaffected by thevertical adjustment of said shaft by reason of the fact that theadjustment is slight.

3. A machine as set forth. in claim 7 wherein the drum shaft bearingsare vertically adjustable relative to the frame elements tocorrespondingly adjust the drum relative to the work, thecounterbalancing means in connection with said link pivotally connectedwith the rocker arm being arranged to be practically unaffected by theendwise movement of said arm required in the vertical adjustment of saidshaft by reason of the fact that the adjustment is slight.

4. In a machine of the character described, the combination of a pair ofspaced frame elements, a shaft received in bearings in said elements andcarrying a rotating abrading drum operating between said elements, a

the other of said links having means for com-' municating a thrustthereto to rock said arm on its pivotal mounting whereby to communicateendwise oscillation to said shaft through the thrust collar thereon, andmeans in connection with one of said links for counterbalancing theweight of said rocker arm whereby to eliminate the weight thereof fromthe thrust collar and hence from said shaft, both of said links beingarranged by slight oscillation to permit straight line motion of the endof said arm pivotally connected with the thrust collar, said drum shaftbeing vertically adjustable with its bearings relative to the machineframe whereby to correspondingly adjust the drum relative to the work,and said counterbalancing means being arranged to be practicallyunaffected by the accompanying endwise movement of said arm by reason ofthe fact that the adjust ment is slight. v

5. In a machine of the character described, the combination of framemembers, a shaftsupported by the latter and carrying an abrading drumfor rotation between the frame members, a thrust collar on one end ofsaid shaft, a rocker arm having a pivotal connection with said collar atits upper end, a link providing a floating pivotal connection for saidarm with the one frame member to permit straight line motion of theupper end of said arm, another link having connection" with'said arm forrocking the same to communicate reciprocatory movement to said shaft,and means cooperating with one of said links to cause the frame toassume the weight of said arm whereby to keep the Weight thereof off thethrust collar.

6. In a machine of the character described, the combination of framemembers, a shaft supported thereby and carrying an abra-ding drum forrotation between the frame members, a thrust collar on one end of saidshaft,

a rocker arm having a pivotal connection with said collar at its upperend, a link providing a floating pivotal connection for said arm withone of said frame members whereby to permit straight line motion of theupper end of said rocker arm, another link hav ing connection with thelower end of said rocker arm for rocking the same so as to communicatereciprocatory movement to said shaft, and a spring reaching from asuitable support to one of said links to yiel-dingly assume the weightof said arm and thus keep this weight off the thrust collar.

7. In a machine of the character described, the combination ofv framemembers, a shaftsupported thereby and carrying an abrading drum forrotation between the frame members, a thrust collar on one end of saidshaft which projects beyond one of the frame members, a verticallydisposed rocker arm having the upper end thereof pivotally connectedwith said collar, a link pivoted at one end on the last mentioned framemember and at the other end on said rocker arm intermediate the ends ofthe latter, providing a floating pivotal mounting for said arm to permitstraight line motion of the upper end thereof, spring means associatedwith said link for counterbalancing said rocker arm to relieve theweight thereof from the thrust collar, a second link having pivotalconnection with the lower end of said rocker arm for communicatingrocking motion to said arm and thereby reciprocatory movement to saidshaft, and means for communicating reciplrgocatory movement to the lastmentioned lin 8. A machine as set forth in claim 7 including a bracketon the frame member having the first mentioned link pivoted with respectthereto, the rocker arm counterbalancacting between said bracket and thelower side of said link.

9. In a sanding machine comprising a pair of frame members, and a shaftsupported thereon and carrying an abrading drum for simultaneousrotation and reciprocation between the frame members; a thrust collar onone end of said shaft for transmitting reciprocatory movement thereto, arocker arm pivotally suspended from said collar, means for pivoting therocker arm relative to the frame for rocking movement, the said meanspermitting a certain amount of up and down movement of the rocker arm inthe rocking thereof to provide for straight line motion of the upper endthereof with the thrust collar, means for assuming the support of therocker arm whereby to relieve the thrust collar of this weight andthereby provide for smooth operation of the shaft, and means for rockingthe rocker arm, the means for assuming the weight of the rocker armcomprising spring means acting between the arm and the frame, the samebeing yieldable to permit the up and down movement of the rocker arm.

In witness of the foregoing I aflix my signature.

PETER A. SOLEM.

mg means comprising a compression spring e

